1. Field of the Invention
The present invention relates to a projector. More specifically, it relates to a projector for modulating and, subsequently, for enlarging and projecting a light beam irradiated from a light source to form a projection image.
2. Description of Related Art
Recently, a projector has come to be used in various circumstances such as technical review meeting at research and development department etc. by enlarging and projecting a data of CAD/CAM/CAE (computer-aided design/computer-aided manufacturing/computer-aided engineering), various seminars and training institutes and classroom lessons in audiovisual education, as well as company meeting and presentation on business trip. Further, the projector has come to be used for projecting medical images and data such as CT scanning (computed tomography scanning) and MRI (magnetic resonance imaging) to serve for studying remedies and medical guidance and for effectively staging exhibitions and events attracting a lot of people.
Since projectors are now used in such various environments, various performance and functions are required for projectors, which include light-weight compact model for improving portability, high-intensity model and high-definition model for improving quality of images and high-function model capable of being connected to various digital machines and mobile tools.
The projectors are expected to be used in wider areas, so that projectors with more values added are now intensely developed targeting new area for use.
The aforesaid projectors accommodate a plurality of optical components thereinside, and modulate, enlarge and project a light beam irradiated from a light source using the source using the optical components to form a projection image.
Such optical components includes a polarization converter for converting the light beam irradiated from a light source via a beam splitter such as a lens array into a predetermined linear polarization beam for improving light utilization efficiency and for eliminating various optical aberrations, and a lens array for transmitting a plurality of partial beam irradiated form the polarization converter to a light modulator such as liquid crystal panel and to superpose the light beam on a display area of the light modulator.
Such polarization converter and lens array are respectively fixed on a inner case supporting the elements at a predetermined position adjacent to the light source. In fixing the elements, the position of the polarization converter and lens array relative to optical axis of the light incident on these elements is adjusted.
However, since the polarization converter and the lens array have to be independently fixed to a dedicated fixing portion while adjusting position thereof relative to optical axis, optical axis adjustment is troublesome. Further, a lot of work is necessary for fixing the components, thus requiring a lot of time for assembling the projector.
Further, since two fixing portions for the polarization converter and lens array have to be provided on the inner case constituting the projector, the structure of the inner case becomes complicated. Especially, since the polarization converter and the lens array have to be very closely disposed, the fixing portion has to be provided closer, so that the structure of the inner case becomes further complicated.
An object of the present invention is to provide a projector capable of enhancing light utilization efficiency, facilitating optical axis adjustment between a polarization converter and a lens array to reduce trouble in securing work and simplifying a structure of a fixing portion of a support.
A projector according to an aspect of the present invention includes:
a light source for irradiating a light; a beam splitter for splitting the light irradiated from the light source into a plurality of partial light beams; a polarization converter for converting the light beam irradiated from the beam splitter into a predetermined linear polarized light; and a lens array including a matrix-shaped arrangement of a plurality of lenses for transmitting the plurality of partial light beams irradiated from the polarization converter to a light modulator, in which the polarization converter and the lens array are integrated and fixed to a fixing portion of a support for supporting the polarization converter and the lens array.
According to the above arrangement, since the polarization converter and the lens array are integrated with optical axis position thereof being adjusted, the polarization converter and the lens array can be attached to the fixing portion of the support only by adjusting fixing position thereof of the integrated unit. Accordingly, it is not necessary to independently adjust the respective positions of the polarization converter and the lens array in the optical axis before attachment as in the conventional arrangement, so that trouble for position adjustment can be reduced, thus facilitating attachment of the polarization converter and the lens array.
Since the polarization converter and the lens array are provided, light utilization efficiency can be enhanced. Further, since the integrated polarization converter and the lens array are attached to the fixing portion, only one fixing portion is necessary, thus simplifying the structure of the inner case.
In a projector of an aspect of the present invention, a fixing position of the integrated polarization converter and the lens array may preferably be adjustable relative to the fixing portion of the support.
According to the above arrangement, since the polarization converter and the lens array can be attached to the fixing portion while adjusting fixing position thereof, while maintaining relative position by setting positional relationship between the polarization converter and the lens array in advance, the optical axis can be easily adjusted thus fixing an appropriate position.
In a projector of an aspect of the present invention, the plurality of lenses constituting the lens array preferably correspond respectively to a disposition of a polarization separation film of the polarization converter.
Since the plurality of lenses corresponds to the disposition of the polarization separation film of the polarization converter, the partial light beam from the polarization converter can be securely condensed and transmitted to the liquid crystal device by the lens array, thus further enhancing light utilization efficiency.
In a projector of an aspect of the present invention, the polarization converter and the lens array may preferably be integrally fixed with a holding frame for holding the polarization converter and the lens array.
According to the above arrangement, since the polarization converter and the lens array are held by the holding frame, mutual optical position of the polarization converter and the lens array can be easily established only by attaching the polarization converter and the lens array to the holding frame. Further, since the polarization converter and the lens array are held by the holding frame, the polarization converter and the lens array can be protected against shock applied from the outside.
In a projector of an aspect of the present invention, a fixing position of the holding frame may preferably be adjustable relative to the fixing portion of the support.
Accordingly, since the position of the polarization converter and the lens array can be adjusted by holding the holding frame, it is not necessary to directly hold the polarization converter and the lens array, so that the surfaces thereof is not likely to be damaged or got dirty.
In a projector of an aspect of the present invention, a guide engaging portion for guiding the holding frame to the fixing portion of the support may preferably be provided to the holding frame.
Since the guide engaging portion is provided to the holding frame, the holding frame is guided by the guide engaging portion in securing the holding frame on the fixing portion, the holding frame can be easily fixed.
In a projector of an aspect of the present invention, a jig engagement portion engageable with a position-adjusting jig for adjusting a fixing position of the holding frame may preferably be provided.
By providing the jig engagement portion, the holding frame can be easily held by the jig always at a constant attitude, so that the position adjustment is further exactly conducted.